ROTATIONAL MOTION

What is the role of the center of mass in gravitational potential energy calculations?

• It has no role
• It doubles the energy
• It reduces energy to zero
• It allows the entire mass to be treated as concentrated at that point

How does the kinetic energy of rotation depend on angular velocity?

• Linearly proportional
• Inversely proportional
• Independent of angular velocity
• It is proportional to the square of angular velocity

What is the angular momentum of a particle moving in a straight line past a point?

• Always zero
• Always infinite
• Depends on mass only
• It is non-zero if the line of motion does not pass through the point

Why is the motion of the center of mass unaffected by internal forces in a system?

• They are too weak
• They act randomly
• They do not exist
• Internal forces occur in equal and opposite pairs that cancel out

What is the direction of torque when a force tends to produce counterclockwise rotation in the xy-plane?

• Along the negative x-axis
• Along the positive y-axis
• Along the negative z-axis
• Along the positive z-axis